1. Field of the Invention
The present invention relates to an apparatus for covering a portion of the cervix uteri to prevent the migration of sperm from the vagina into the cervical canal and more particularly to a cervical cap having a ridged section adapted to grip the cervix, thus preventing dislodgement (or displacement) of the cap (or thus increasing cap stability).
2. Description of the Related Art
Cervical caps designed to cover a portion of the cervix uteri in order to prevent the migration of sperm from the vagina into the cervical canal and thereby prevent conception are known in the art. However, these known caps suffer several drawbacks and deficiencies.
Known cervical caps create medical problems for the user, such as abnormal cramps, abnormal bleeding, abnormal discharge from the uterus, and mucosal erythema. Furthermore, known caps, due to their size and shape, cause discomfort for both the user as well as for the partner.
Another problem encountered with prior cervical caps is the frequency with which they become dislodged from the cervix. These caps rotate on the cervix or slide from the surface of the cervix when the rim is gently pushed. The result of such dislodgement is not only increased discomfort but the defeat of the very purpose behind using the cervical cap because dislodgement allows sperm to migrate into the cervical canal which can result in conception.
Therefore, attempts have been made to design a reliable cervical cap that securely fits around a portion of the cervix while still avoiding the aforementioned medical problems and the associated inconveniences and discomfort. Such attempts have taken a variety of forms. For example, some caps have been designed with a spring mechanism within the wall; some caps have been provided with adhesive to adhere the cap to the cervix (see, for example, U.S. Pat. No. 3,952,737); and some have been provided with projections on the inner surface. However, these caps have not only failed to solve the problems discussed above, but have created additional problems. For example, U.S. Pat. No. 3,952,737 discloses a cervical cap which is held to the cervix by an O-ring, notches, an internal bead and an inner sealing ring. This device, however, in attempting to solve the dislodgement problem, has resulted in a cap that is both expensive to manufacture due to its complexity and is difficult to use because it is inserted with an applicator and the 0-ring must be maneuvered from the bottom position to the top position after the cap has been placed on the cervix.
A need therefore exists for a cervical cap that is comfortable and reliable as a contraceptive. Furthermore, a need exists for such a comfortable and reliable cap that is simple to use, is not prohibitively expensive, and does not adversely affect the health of the user.